In the copending patent application, Ser. No. 06/275,693 filed June 22, 1981, which has one inventor (Sheldon G. Shore) in common with this application and which is assigned to the same Assignee as this application (the disclosure of the aforementioned application Ser. No. 06/275,693 being incorporated herein by reference), the prior art relating to the reactions of H.sub.2 Os.sub.3 (CO).sub.10 is reviewed. This prior art indicates that H.sub.2 Os.sub.3 (CO).sub.10 normally reacts as a Lewis acid.
The aforementioned application Ser. No. 06/273,693 demonstrates for the first time that H.sub.2 Os.sub.3 (CO).sub.10 also possesses apparent Lewis base character and discloses a process for making a tri-osmium heteronuclear metal carbonyl compound which comprises establishing a reaction mixture comprising an electron deficient cobalt, nickel or iron carbonyl or a cobalt, nickel or iron carbonyl anion, H.sub.2 Os.sub.3 (CO).sub.10, and a solvent which at least partially solubilizes at least one of the electron deficient carbonyl compound and the H.sub.2 Os.sub.3 (CO).sub.10, the H.sub.2 Os.sub.3 (CO).sub.10 reacting with the electron deficient carbonyl compound as a Lewis base, and recovering the tri-osmium heteronuclear metal carbonyl compound from the reaction mixture. Among the specific examples of this process described in detail in the aforementioned application are the reaction of Co.sub.2 (CO).sub.8 and H.sub.2 Os.sub.3 (CO).sub.10 to produce a major proportion of HCoOs.sub.3 (CO).sub.13 and a minor proportion of H.sub.3 CoOs.sub.3 (CO).sub.12, and the reaction of [(.eta..sup.5 -C.sub.5 H.sub.5)Ni(CO)].sub.2 with H.sub.2 Os.sub.3 (CO).sub.10 to produce H.sub.3 (.eta..sup.5 -C.sub.5 H.sub.5)NiOs.sub.3 (CO).sub.9. The yield of H.sub.3 CoOs.sub.3 (CO).sub.12 in the first of these two reactions is only about 5%, while the yield of H.sub.3 (.eta..sup.5 -C.sub.5 H.sub.5)NiOs.sub.3 (CO).sub.9 in the second reaction is about 50%.
We have now discovered that, by carrying out the reaction described in the aforementioned application using the electron deficient carbonyl in the presence of gaseous hydrogen, the yields of certain of the tri-osmium nuclear metal carbonyl compounds produced can be markedly increased, and new carbonyls produced. In the case of the reactions described in the aforementioned application which produce a mixture of two products, the ratios between the two products can be shifted dramatically, so much so that in some cases what was formerly the minor product of the reaction becomes the only detectable product thereof. Furthermore we have also found that, by carrying out the reaction in the presence of hydrogen, carbonyls of metals other than cobalt, nickel or iron may be employed in the reaction.